Fuel pump



Sept.21, 1937. PARSONS 2,093,477

FUEL PUMP Filed Jan. 16, 1936 4 Sheets-Sheet 1 Z J zi INVENTOR. 'fif/V 6'. P430 0/141 ATTORNEY.

Se t. 21, 1937. B. e. PARSONS 2,093,477

FUEL PUMP File d Jan. 16, 1936 4 Sheets-Sheet s .7 if f/ 2 2 2a ATTORNEY.

Se t. 21, 1937. B. a. PARSONS FUEL PUMP Filed Jan. 16, 1936 4 Sheets-Sheet 4 INVENTOR. 501/ a. emra/w Q. )4. @114 ATTORNEY.

. Patented Sept. 21, 1937 UNITEDSQTATES PATENT OFFICE Ben G. Parsons,

Detroit, United American Bosch Corporation, Spring- Mich., assignor to field, Mass, a corporation of New York Application January 16, 1936", Serial No. 59,350

11 Claims.

I This invention relates to fuel pumps and has for its principal obj ect to provide an improved directly into each of the cylinders or adjacent to the-intake ports thereof.

A further object of this invention is to provide a pump of this type which because of'its reduced number of machined parts and drilled passageways permits a reduced cost of construction, and

which may be easily further object is to assembled and repaired. A

provide for the lubrication,

and cooling of such pumps thereby insuring their durability and operating efiiciency.

Other objects and features of the invention will in part be obvio and in part be set us to those skilled in the art forth in conjunction with the following detailed description.

In the accompanying drawings there is shown for purposes of illust bodiment of the present invention, it being understood that these ration a single preferred emdrawings do not define the limits, as changes in the construction and operation disclosed therein may be made without departing either from the spirit of the inventionor the scope of the broader claims.

In the drawings:

Fig. 1;

Fig. 3 is a similar longitudinal section with of Fig. 2;

Fig. 4 is an elevati parts in side elevation taken on the line 3-3 on of the fuel pump showing the control lever side thereof;

Fig. 5 is a transverse section taken on line 5-5 of Fig.

- Fig. 6 is an end viewof the mounting end of the pump;

Fig. 7 shows the plungerhousing assembly in side elevation;

Fig. 8 is atransv Fig. 1; r

erse section on line 9-9 of Fig. 9 is a detail showing the plunger cup retaining ring;

Fig. 10 is a view showingthe discharge tubes as assembled in the course of manufacture;

Fig. 11 is an end view of the same;

Fig. 12 is a detail showing the delivery valve and its guiding spri and ng, upon an enlarged scale;

I open providing Fig. 13 is a detail showing the plunger housing end plate.

Referring to the drawings, l indicates an outer cylindrical pump' casting forming a housing for a-cylinder block H. The cylinderblock I l is provided with a relatively large central bore l2 extending therethrough, and a plurality of smaller bores l3 which form the pump cylinders arranged symmetrically therearound. Pistons M are 'reciprocative in the cylinder bores. 13, being actuated by a swash plate I mounted upon a central shaft l6, which is adapted to be driven from the cam shaft of the engine. The shaft l6 extends into the central bore 12 and carries a sleeve ll splined thereon. The sleeve .ll constitutes a control member for regulating the quantity of fuel supplied by the pump, as will be hereinafter more particularly described, and also provides a journalinthe bore l2 for one end of the shaft 16. A second journal for the shaft 16 is provided with ball bearings 18 in end plate I9 which closes one end of the pump casting ID. A cap 20 closes the opposite end of the housing IO,

being fastened thereto by bolts 2|.

An annular boss 22 on the end cap provides a connecting means for a suitable supply pipe, not shown, and opens into a cavity 23 containing one or more filters 24. A longitudinally extending passage 25 in the housing It) connects the discharge side of the filter chamber 23 with a cross bore 26 located between the ends of thehousing 10. The outer end of cross bore 26 is plugged or otherwise closed and the inner end opens into an annular groove 21' formed in the inner surface of said housing. At a point adjacent the groove 21,

I the cylinder block I l is provided with a deep annular groove 28 which projects into the block II to a depth greater than the diameter of the cylinder bores l3 together with their distance from the outer wall of the block. The cylinder bores are thus surrounded by a fuel space and are in free communication therewith, when not obstructed by pistons 14. v

The pistons M are hollow, providing chambers 29in the interior-thereof. Ports 30 which register with the space formed by the groove 28 when the pistons 14 are in theiroutermost positions provide communication between the grooves 29 and chamber 29 when the pistons are in this'po sition.- [The inner ends of the pistons l4 are free communication, between the chambers 29 and the interior of cylinders 13 at all times. Radially extending bores 3i connect the cylinders l3 with the central bore 12 at points beyond the innermost travel of the pistons l4.

trol member I! for a period which depends upon 2 The outer ends of the radial bores forming passages 3| are closed by plugs 32 and the inner ends open into a chamber 33 formed between the walls of the central bore l2 and reduced portion 34 of the control member H. The ends of the control member I] on both sides of the reduced portion 34 completely fill the. central bore l2 with the minimum possible clearance therebetween. The reduced portion 34 of the control member I! is so cut as to leave a projecting surface 35 having one edge 36 parallel to the axis of the control member and another edge 31 at an angle thereto. The projecting surface.35 is therefore capable of obstructing each .of the passages 3l once during each revolution of the con- -'the longitudinal position of the control member.

The control member l1 maybe adjusted longitudinally by means of a flexible member 38, one end of which carries a fitting 39 journaled in ball bearings 40 positioned in the end of control member I1 beyond the end of shaft Hi. The fitting 39 is held against longitudinal movement relative to ball bearing 40 by spring rings 4| and 42 attached thereto on either side of the bearings so that the control member l1, while capable of rotation relative to the flexible member 38, is.re-,

sponsive to longitudinal movements-otthe'latter. An end cup 43 attached to cylinder block II by screws 44 provides a cover for the end of control member I! and has an annular projecting portion 45 for supporting one end of a tubular cover 46 forthe flexible member 38. A bracket 41 provides a further support for the tubular cover 46, at about the central portion thereof. As shown the flexible member bends in a space provided by cap 28 so that the outer end thereof may be attached to an arm 49 of a control shaft 50 which ond set of radial bores 5| in the cylinder block II passes between each of the cylinders l3 con- 1 necting the chamber 33 with an annular groove 52 in the housing ID. A passage 53 connects the annular groove 52 with a longitudinal bore 54 in the housing I. The bore 54 registers with a bore 55in the cap 20 and an annular boss 56 disposed opposite the boss 22 provides a connecting meansbetween the passage formed by bore 55 and a suitable overflow pipe not shown.

The discharge ends of the cylinders 13 are closed by an annular plate 51 having orifices 58,

- one of which orifices is disposed axially of each of the cylinders I3. The plate 51, details o1 which are shown in Fig. 13, is groundand lapped on both sides so "as to form a tight joint with both the cylinder blocks II on one side and a member 59,v cast integrally with the-housing III,

on itsopposite side. Adjacent each of the orifices 58, cavities 80 8.143 formed for the accommodation of delivery valves 8|. The delivery valves 6|, details of which may be seen in Fig. 12, are

formed. with flat surfaced valve heads 62 which normally seat against the smooth surface of plate 51 to close the discharge orifices 58. Such seatmg is efiected by ribbon springs 63 surrounding fuel flow Furthermore I have found that fuels valve stems 64, which stems are relatively short projects through the side wall of cap 20. A sec-' plungers are driven by a common swash plate,

the plungers will be actuated on their working strokes successively in regular order in the direction of rotation of the drive shaft. It will also be evident to those skilled in the art that this order does not coincide with the flring order of conventional four cycle engines of the type having nine radial cylinders, such firing order being 1-35-'7-9--24-6-8. A- further complication arises if the pump, which is driven at half crank shaft speed in the case of a four cycle engine, rotates in the reverse direction to that of the crank-shaft. It will be seen that'if each of the tubes 65 leads straight to one of the discharge connections 68 on the outer circumference of the housing In, a network of criss-crossing tubing outside of the housing I0 would be necessary in order to connect each of the discharge connections 66 with the proper engine cylinder. Such I a network'would tend to interfere with ready access to other engine parts. In order to avoid this and to reduce the length of tubing exposed to injury and rupture outside of housing III, the tubes 65 are bent within the housing Ill and each of them is directed to such of the discharge connections 66 that the fuel line. between this con-' nection and the proper engine cylinder may be as direct as possible and need not cross any other fuel line.

In order to avoid numerous and expensive bores in the housing I 0, which would otherwise be necessaryto connect the discharge cavities 68 with the proper discharge connections 66, and to effect other objects hereinafter mentioned, the

tubes 85 are preformed of durable material such.

as stainless steel bent in the directions necessary to connect the cavities 80 with'. the properdischarge connections 66. The tubes so formed are brazed, welded or otherwise securely attached at the ends thereof to the member 58 and to the discharge connections 66. The resulting structure which may be seen in Figs. 10 and 11 is in-'-- serted in the mold for casting the housing I0 and the casting is then formed thereabout preferably of aluminum-magnesium alloy.

Such construction of housing member Il results in a great saving in cost over previous constructions. It also results in greater strength in proportion to weight for numerous borings in housing In would weaken.the structure and re- -quire a heavy casting whereas the steel tubes provide reenforcement for the light metal casting giving a strength where most needed. Also'the steel tubing can be formed to provide smooth rounded corners at: the bends whereas the passages which would result from boring the housing III in the necessary directions would'have sharp angled corners detrimental to high velocity the relativelyilow pressure spill passages 54 and 55 are formed in aluminum castings but none of the parts in contact with the fuel under substantial pressure are of such material.

The ends of the plungers ll are rounded as indicated at 61. Plunger cups 68 are interposed between these rounded ends and the swash plate 15. In operation springs 69 .press the plungers order that the cups may be handled as a unit, I

' provide each of the same with an outer circumferential groove Ill, and an annular plate II is provided with a series of deepsubstantially circu lar cuts 12 in its outer circumference as may be seen in Fig. 9. The cuts 12 extend into the plate II to a depth substantially greater than the radius of the circle which defines the curvature of the cut. :The internal radius of grooves I corresponds approximately to the diameter of the circular cuts 12, so that in order to insert the cups in the retaining plate H, the outer edge of the latter must be sprung slightly so that the cups-X once in position will be firmly held in place. In operation, when aplunger is in the position shown in Fig. 1, fuel flows from the annular groove 28 through the port 30 of the hollow plunger l4, fillingthe same and the pump cylinder l3. As the plunger is forced inwardly by the swash plate IS, the fuel first flows through the radial passage '3! intothe chamber 33, formed by the reduced- I portion 34 of the control member II. The fiow continues until about the mid position of the discharge valve 3i closes. and for the remainder plunger stroke when the leading .edge of v the projecting surface 35 passes the discharge end of radial passage 31. Flow in this direction isthus cut off, pressure in the pump cylinder l3 at once builds up to a point where the'discharge valve Si is opened against the pressure of spring 63, and fuel flows through the tube 65 and thence to the proper engine cylinder. As the trailing edge passes the discharge'end-of radial passage 3|, communication between the pump cylinder I3 and the chamber "is again opened. The pressure in the pump cylinder is at one reduced, the

of the stroke the'fuel flows through the chamber 33, radial bores 5| annular groove 52 and by way of passage 53 to the longitudinal bores 54 and 55 in housing Ill and end cap 20, from which it returns Inna-suitable pipe, not shown,-to thesupply tank or other suitable container. It will be seen' that the duration of the portion of the plunger stroke which is efi'ective in supplying fuel to the engine is dependentupon the longitudinal position of control member I'I. Regardless of whether this member is adjusted for light' or full load, there is always a considerable quantity of fuel passing through the spill-passages above described and this fuel. passing through and around the' pump cylinders in the manner I described tends to cool the same and prevent binding of the pistons H which reciprocate in cylinders I 3 with the minimum possible clearance therebetween. I i I At the ends of control member II on each side of the chamber 33, the internal grooves I3 in the bore I! of the cylinder block ll collect any leakage flowingalong the control'member II. Bores 14 and is in the cylinder block ii and member 59 conduct this leakage to the :bore 54 forming part of the spill passage. .It will be understood that pressure in chamber 33 is somewhat higher than pressure in the bore 54.

acoaiw 1 of fuel around either end of the control member,

while the grooves 16 prevent leakage of fuel around the ends of the pistons ll. The lubricant of the swash plate and associated mechanism is therefore not contaminated by the fuel.

A timing pin 'I'l projects .through the housing. I0 adjacent thefianged end thereofand may be manually depressed until the inner rounded end thereof contacts with the outer surface of a disk l8. The disk 18 is integrally withor.otherwis'e rigidly secured to the shaft i B and is provided with a notch in its outercircumference so'positioned that when the timing pin is depressed and the. shaft it slowly rotated the rounded end of the v pin will drop into the notch when the piston of number i pump cylinder is-in a predetermined position correspondin for example, to the beginning of the eflecti e-working stroke of said. piston. The operator, therefore, may readily determine the proper timing of the pump with respect to the engine. 1

'Havingthus described the invention, whatis claimed as new is: 1. In a pump of the typehaving a plurality of cylinders extending parallel to and surrounding a common shaft, an annulancylinder-block having bores forming said cylinders, a casting surrounding said block, a closure for said casting providing a bearing for said shaft, an output control member common to all cylinders splined von said shaft and providing a second bearing therefor, means to lubricate said shaft, and means to prevent contamination of the lubricant by fluid from a 2. In a pump of the type'having a. plurality of cylinders extending parallel to and surrounding a common drive shaft, an annular cylinder block surrounding said shaft, and an outer annular casting surrounding said cylinder block and con-- taining all inlet and discharge connections there- 3. In a pump of the type having a plurality of 0 cylinders extending parallel to and surrounding a common drive shaft, an annular cylinder block cylinders, an annulanpasting surrounding said 60 block, and'tubes constituting discharge passages preformed and cast integral with said annular casting. T

5. In a pump of the type. having a plurality of cylinders parallel to a common drive shaft, an annular cylinder block containing said cylinders,

a casting surrounding said block, a cap attached to one end of said casting and providing a bearing for said shaft, and an'output control member common .to all cylinders splined on said shaft and providing a second bearing therefor. v

6, In.a pump of the type having a plurality of I cylinders extending parallel to and surrounding a common drive shaft, plungers reciprocative in said cylinders, a swash plate on said shaft for 5 7. In a pump of the type having a plurality of cylinders extending parallel to and surrounding a common drive shaft, plungers reciprocative insaid cylinders, a swash plate on said shaft for actuating said plungers, plunger cups between i said plungers and said swash plate, said cups having annular grooves in the circumference thereof, and an annular disk having portions coacting with each of said grooves to retain said cups in position. j

a 8. In apump of the type having a plurality of cylinders extending parallel to and surrounding a common shaft, pistons reciprocating in said cylinders, an output control member common to all cylinders s lined on said shaft, and a flexible rod for shiftingfsaid control member.

9. In a pump of the type having a plurality of cylinders extending parallel to and surrounding a common shaft, pistons reciprocative in said cylinders, an output control member common to all cylinders splined on said shaft, ,a flexible rod for shifting said control member, a housing enclosing said flexible rod, an oscillable control plate to close said orifices.

shaft projecting through a lateral wall of said housing, and an arm on the inner end of .said shaft to which said flexible rod is attached.

10. In a pump of the type having a plurality of cylinders extending parallel to and surrounding a common drive shaft, an annular cylinder block having bores forming said cylinders, a casting surrounding said block, an output control member common to all cylinders mounted on said shaft, and means whereby a portion of the fuel acted upon by said plungers passes therearound for cooling the same.

11. In a pump of the type having a plurality of cylinders extending parallel to and surrounding a common drive shaft, an annular cylinder block having bores forming said cylinders, a casting surrounding said block and having an integral end portion containing discharge cavities for each of said cylinders, a flat annular plate secured between said cylinder block and said end portion, said plate having an opening coaxial with each of said cylinders, and discharge valves in said cavities seating against the flat surface of said BEN G. PARSONS. 

